In general, filters are used to remove contaminants, such as debris, from a flow of liquid. Filters have been used in hydraulic systems, engine lubrication systems, and engine fuel systems. Filters can be used to remove contaminants from. can remove contaminants from engine oil, transmission oil, lubricating oil, hydraulic oil, or a supply of fuel to or from a fuel pump. Other vehicle hydraulic systems, such as those in automatic transmissions and power steering, are often equipped with an oil filter. Spin on filters typically thread onto a manifold for a single use, before removal and replacement.